Find the 29th term of the following sequence. 13.1,3.1,-6.9,-16.9

Consider this option:
1. this arithmetic sequence consists of b1;b2;b3;b4;...;bₐ, where b1=13.1; b2=3.1; b3=-6.9; b4=-16.9, etc. and the difference (d) between bₐ₊₁ and bₐ is (-10).
2. using formula for bₐ of arithmetic sequence: bₐ=b₁+d(a-1), where a - number of term of this sequence, it is possible to find b₂₉: b₂₉=b₁+d(29-1)=13.1-10*28=-266.9.

-266.9

Find the perimeter of the figure shown above with a side length 5 units.(each figure is a square).a.10 unitsc.30 unitsb.20 unitsd.40 units select the best answer from the choices providedabcdmark this and return